Warheads with shaped-charge munition, also known as hollow charge munition, are known to pierce enclosures such as armor and thereby destroy the protected object from within. This capacity of a shaped charge results from the fact that upon detonation there forms an energy-rich jet also known as “thorn” or “spike” which advances at very high speed of several thousand meters per second and is thereby capable of piercing even relatively thick armor walls.
Several arrangements have become available in recent years to afford protection against the penetrating effect of an exploding shaped charge. Examples of such arrangements are disclosed in U.S. Pat. Nos. 4,368,660, 4,741,244, 5,070,764 and 5,637,824, to the same inventor as of the present invention.
All of these prior art reactive armors are concerned with a structure holding at least one reactive armor element wherein the reactive armor element comprises an array of layers comprising one or more plate layers and at least one layer of explosive material tightly bearing against at least one of the plate layers. The plate layers are made, for example, of metal or a composite material. A basic reactive armor element comprises two metal plates sandwiching between them the layer of explosive material. Such prior art reactive armor elements are based on the mass and energy consuming effects of moving plates and their functioning is conditional on the existence of an acute angle between the jet of an oncoming hollow charge threat and the armor itself.
According to some variations, the reactive armor element is a multi-layer composite body in which each layer tightly bears against each contiguous layer, wherein the multi-layer composite body includes an outer metal cover plate, at least one explosive layer, at least one intermediary inert body adjacent to each of the at least one explosive layer and which is thicker than an aggregate thickness of the outer cover plate and any adjacent explosive layer, and a metal base plate, whereby on initiation of the explosive layer a succession of dynamic collapse cycles occurs in which at least one intermediary inert body collapses into a crater formed by a penetrating jet originating from an oncoming shaped-changed warhead.
Reactive armor elements of the concerned types thus disclose an arrangement wherein the explosive material tightly bears, in a sandwiching-like manner, between neighboring layers of plate members, this being a condition for effectively handling the threat of an oncoming shaped-charge warhead.
However, a problem occurs when for some reason the explosive material disengages from the adjoining plate layer. Such reasons are, for example, loose contact between the explosive layer and the bearing plate, absence of adherence therebetween, deformation of the bearing plate e.g. by a kinetic projectile (shrapnel, bullets, etc), a weak jet of a shaped-charge warhead which fails to detonate the explosive material although its impact on the plate, or even on the explosive material, will deform one or both of the plate members and the explosive material, etc. Upon deformation of the plate member or of the explosive layer, and disengagement/detachment from one another, the reactive armor element loses its effectiveness against reactive armor element.
Furthermore, in some cases the jet will not initiate the armor element. For example, the armor element may be struck at an area which is lacking explosive material or comprises a thin layer or where the explosive material detaches from the plate, e.g. upon deformation of the plates owing to mechanical impact by shrapnel, kinetic warheads, etc.
It is thus an object of the present invention to provide a reactive armor element with improved resistance to non-detonating attack, i.e. where the explosive layer detaches from the bearing plate layer and does not detonate. It is a particular object to provide improved contact of the explosive material with the respective plate member, and to minimize the damage of a reactive armor element to local damage only, in case of a non-detonating attack. The invention is further concerned with a method utilizing a reactive armor according to the invention.